John,
There is indeed a 10 Hz limit on resolution in the CAT, set by the firmware.
However, that should not be a problem. All the many TLM programs I have
used in the past have worked well with 10 and even 100 Hz step sizes. My
impression is that RASCAL could do with a little tweaking of the PLL values,
but that may be more of an indicator issue. My experience is that is will
in fact decode nicely, even though the Sync indication blinks off. FWIW
Alan
WA4SCA